Thread-like suture materials are used as standard in surgery for closure of wounds. They are usually knotted to be securely fixed in the tissue. Care has to be taken to ensure that the wounds to be closed are sutured with an optimal force at the wound margins. If the wound margins are sutured too loosely and too irregularly, for example, there is in principle a risk of increased scar formation or dehiscence. By contrast, if the wound margins are sutured too strongly, there is a danger of the circulation of blood in the wound margins being restricted, which can result in necrotic changes in the surrounding tissue area.
In addition to the risk of possible complications, in particular further surgical interventions, there is therefore always a degree of risk of the wound repair, based on knotting of suture materials, leading to impaired healing and to unsatisfactory cosmetic results in the patients concerned. Another consideration is that several knots, in particular up to seven knots, often have to overlap to achieve a secure knot hold. This entails introducing a large amount of material into the area of the wound that is to be treated and can lead to increased foreign-body reactions, particularly in the case of resorbable suture material.
Suture materials which, in contrast to known or conventional threads, do not have to be knotted have long been known as “barbed sutures.” Such knotless or self-fixing suture materials are usually composed of a monofilament thread which, along its longitudinal axis, has structures called ‘barbs.’ Corresponding suture materials are described, for example, in U.S. Pat. No. 3,123,077 A, EP 1 559 266 B1, EP 1 560 683 B1 and EP 1 555 946 B1. The barbs are formed on a thread such that the thread can be pulled through the tissue along the direction of the barbs without any great resistance and without tissue trauma. When a pull is exerted in the opposite direction, however, the barbs stand upright and anchor themselves, and therefore also the suture material, in the surrounding tissue area. This ensures that the suture material cannot be pulled back through the incision channel.
To produce the barbs, cuts are made into a drawn thread material. A problem here is that the thread material, because of its being drawn, has an already narrowed diameter, with the result that cutting into a thread material of this kind may cause problems in terms of mechanical load-bearing capacity if the thread is cut too deep. If the barbs are cut too deep into the suture material, even the slightest loads can lead to a tearing of the cuts and, consequently, to a destabilization of the suture material. In extreme cases, breaks may appear in the suture material.
It could therefore be helpful to make available a knotless or self-fixing suture material which avoids the disadvantages known from the prior art and in particular provides sufficient safety and load-bearing in wound closure. Moreover, it could be helpful to make available a corresponding method of production which has clear advantages over the conventional methods for production of knotless suture materials.